Inflatable rubber article



Nov. 1 1932- L. KELEMEN ETAL INFLATABLE RUBBER ARTICLE Filed June-29.1929 2 Sheets-Sheet 1 1932- L. KELEMEN ET'AL 8 INFLATABLE RUBBER ARTICLE Fila d June 29, 1929v 2 Sheets-Sheet 2 Patented Nov. 1, 1932 UNITED STATES PATENT oFFIca LEWIS xnnnxmr .um 20mm xnnn'rr, or BUDAPEST, HUNGARY i mrmrnnn RUBBER an'rrcnn Application filed June 29, 1929, Serial Ho. 874,795, and in Great Britain June 29, 1928.

This invention relates to inflatable rubber articles and more particularly to articles such as toys simulating human and animal shapes having projecting parts or limbs oil- 5 set fromthe median plane of the shape.

It has been proposed to produce such infiatable toysfrom rubber sheets by interposing between a pair of superposed unvulcanized sheet rubber forming the sides of the article, a doubled sheet of like material adapted to form the inner faces of the pro'ecting parts, such as the legs of a toy and t en by cutting the superposed sheets to the desired shape and simultaneously uniting the side parts with the respective parts or the intermediate sheet. According to earlierproposals, the doubled intermediate sheet has been formed by folding a rubber sheet along a straight line. 'lhe straight fold, however, caused distortions in the shape of the indated toy. In order to obviate this, it has been proposed to make the doubled insertion of two sheets united along a curvilinear seam. Such a well known inflated rubber toy as an example in the shape of a quad- 'ruped is shown in Fi l of the annexed drawings in a sections? perspective view.

lhe invention is described with reference to the annexed drawings, in which:

Figure 1 is a sectional perspective view of an inflated rubber toy of well known construction; V

Figure 2 is a sectional perspective view illustrating prior constructions;

Figure 3 shows as an example a cutting die for the production of inflatable toys in the shapeofacat;

Figures 4 and5 are cross sections on the lines 4-4 and 5-5 of Fig. 3 respectively;

Figure 6 is a plan-view of the strip adapted to form the folded insertion; I

Figure 7 is a cross-sectional elevation on the line 5-5 of Fig. 3 of the superposed rubber sheets with interposed cutting die,

I before cutting;

Figure 8 is a fragmentary plan-view of a modification of the cutting die shown in Figure 3; and

Figures 9 and 10 are cross-sections on lines 9-9 and 10-10 respectively of Fig. 8.

Withreference to Fig. 1, a and a are the two side sheets the outlines of which correspond to the outlines of the side elevation of the quadruped. b and 6 are the two lobes of the insertion which are attached 55 along a curvilinear seam c to each other and by means of seams d and (i to the side sheets a and (1 respectively. The insertion sheets b and b form-the inner faces of the limbs offset from the median plane a:w of the shape. Preferably the doubled insertion 1), 5 is formed, as to be seen in Fig. 1, by a bilobate ring extending along the whole circumference of the shape. Such shapes possess three seams situated in three different planes, that is to say the seam c in the median plane m-w, the scams (2 and ti at either side of said median plane. The middle seam c has been found hitherto unavoidable in order to avoid the distortion in shape 7 caused by insertion sheets doubled along a straight folding line, which of course could. not follow the curvatures of the shape to be reproduced. I

While insertions composed of the sheets united along a curvilinear seam obviate the said drawback of folded insertions, this result is reached only by increasing the number of the seams and thereby of the weak spots of the toy. a 39 Especially the median seam c, the ed e of which is turned towards the hollow o the shape, is liable to come apart. Experience shows that seams with the edge directed towards the hollow of the inflated shape are less resistant than outwardly directed seams. Moreover, broad and flat seams d as shown in the sectional perspective view in Fig. 2, are preferably used in such prior proposals. In such seams the rubber sheets a and b adhere to each other not only at their cross sectional area corresponding to the thickness it of the sheets, but at their side faces along a strip of a greater breadth 70 than the thickness it. Such seams do not disfigure the shape as'far as they are used at the lateral seams d, d but they oughtto be avoided at the median seam 0 because this latter generally has to follow more minute details of mo the advantage of the insertion formed by a folded single sheet and the advantages of insertions composed of two sheets united along a curvilinear seam, while avoiding the drawbacks of either of these insertions.

According to the invention the insertion consists of a single rubber sheet bent along a curvilinear fold following the outlines of the median plane of the uninflated article.

In order to manufacture articles provided with such insertions, said insertion is formed preferably of a rubber strip of varying breadth in conformity to therequirements in breadth of the different sections of the insertion. This strip is then folded and applied alon the curvilinear edge of the inner outlines o a ring-shaped die, which determine the median section through the hollow body to be manufactured in the plane of the uninflated articie.

With reference to Fig. 3, j is a metal plate the outer outlines m of which foilow the outer outlines of the inflatable cat-shape in its uninflated flatly foided state. N is an aperture in plate The outlines of said aperture foilow the outlines of the hollow of the shape to be produced in its uninflated, flatly folded state. Cutting edges p, p protruding fromthe plane of plate-j atits either face follow the outlines m of the shape to be cut. The outlines o of the aperture n are used as the shaping edge at folding of the insertion piece.

This latter is formed of a strip u of unvulcanized rubber sheet (Fig. 6) the length L of which corresponds to the iength of the circumference of the shape to be cut with the die. The breadth of this rubber strip varies A along its length. The parts A and B of the strip u which are to form the inner sides of the legs, have a breadth 21, that is to say the double of the length of said limbs (Fig. 3). At the part C (Fig. 6) intended to form the ears, the'brcadth of the strip u is 2.3, that is to say the double of the length 8 (Fig. 3) of the ears. At the remaining sections the strip u has only a very small breadth t, not more than suflicient to cover the die and its shaping edge at their smallest cross sectional areas (Fig. 4) The insertion stri u is folded along the sha ing edge 0 of e aperture n L of the die (Fig. 3) by applying the median line a: m of the strip u to the edge 0 and covering. the flanges of the sections 1-2, 34 and 56 of the die corresponding to the hind legs, the fore 'legs and the ears res ectivel with the two lobes of the extensions A, and C respectively of the strip u, as

it is shown with dotted lines in Figs 3, 4 and 5.

The folding line. of strip u can be easily shaped in conformity to the curvilinear shaping edge 6, because the broad sections A, B

and C of the strip u are relatively short, while the longer sections 7-1, 2-3, 4-5 and 67 of said strip have a small breadth t. The edges of the strip u extending beyond the outer outlines m of the die are pressed together at the. hatched spots w, so that they stick together and secure the position of the insertion on the die.

Thereupen a press plate 31 (Fig. 7) is covered with an unvulcanized rubber sheet 2 and the die j provided with the folded insertion strip u in the above described manner, is put on said first sheet z-. and the whole is covered with a second unvulcanized rubber sheet 2 The superposed parts are pressed between the plate 3 and an upper plate l whereby the cutting edges p, p of the die are cutting through insertion strip u and the side sheets 2 2 and unite at the same time the respective rubber sheets along the cutting lines.

By this cutting a shape is produced which has a bilobate insertion piece extending along the whole circumference of the side elevation similar to that shown in Fig. 1, with the difference, however, that instead of the curvilinear median seam 0' the insertion possesses a curvilinear fold. Hence the insertion in spite of consisting of a single sheet is doubled along a curvilinear fold.

Figs. 8, 9 and 10 show a modification of the die, which can be produced easily by bending a wire i of trapezoid cross section along the cutting outlines of the die, the shaping edge 0 being formed by a second wire 9 of circular cross section with a smaller diameter than the breadth of the cutting wire 2' between the edges p, p. The inner wire q is soldered to the outer wire 11 at the sections in which both wires are running parallel, while at the diverging sections the shaping wire (1 leaves the cutting wire 2' and overbridges the parts of the cutting die which form the limbs or protruding parts of the shape.

In the above example a method described according to which a single insertion strip is used which extends over the whole median circumference of the shape to be produced. Separate insertion pieces, however, can be used for each of the protruding parts A, B, C, because the position of the several insertions can be fixed on the cutting die, so that no difliculty arises in using a plurality of insertions.

Instead of covering the cutting die, which is at the same time the shaping die for the insertion, with a sheet of unvulcanized rubber, the cutting die can be provided with a coating of unvulcanized rubber byany other known method for coating with rubber, for example by dipping.

The inflatable shape produced in the above described manner is vulcanized and finished in the usual way and is provided with a tube or valve for purpose of inflation.

III

What we claim is:

An inflatable rubber toy simulating human or animal forms having projecting parts or limbs ofi'set from the median plane of the article, comprising two side pieces of sheet rubber shaped according to the side outlines of the article in its uninflated state, and m intermediate piece inserted between and secured to said side pieces along their outlines to form the faces of the projections or limbs turned towards the median plane of the article, said intermediate piece comprising a single rubber sheet, extending completely around the article, bent along a curvilinear fold following the outlines of the median plane of the uninflated article.

In testimony whereof I afix m signature.

ZOLTAN' LET'I.

In testimony whereof I aflix my si atm'e.

- V LEWIS KELE N. 

